ZENS. IV. SIMILAR MORPHOLOGICAL CHANGES ASSOCIATED WITH MASS QUENCHING AND ENVIRONMENT QUENCHING AND THE RELATIVE IMPORTANCE OF BULGE GROWTH VERSUS THE FADING OF DISKS*

The Astrophysical Journal American Astronomical Society 818:2 (2016) 180

Authors:

CM Carollo, A Cibinel, SJ Lilly, A Pipino, S Bonoli, A Finoguenov, F Miniati, P Norberg, JD Silverman

TURBULENT AMPLIFICATION AND STRUCTURE OF THE INTRACLUSTER MAGNETIC FIELD

The Astrophysical Journal American Astronomical Society 817:2 (2016) 127

Authors:

Andrey Beresnyak, Francesco Miniati

Dense plasma heating by crossing relativistic electron beams

Physical Review E American Physical Society 95:1 (2016) 013211

Authors:

Naren Ratan, Nathan J Sircombe, Luke A Ceurvorst, James Sadler, MF Kasim, J Holloway, Matthew C Levy, R Trines, R Bingham, Peter Norreys

Abstract:

Here we investigate, using relativistic fluid theory and Vlasov-Maxwell simulations, the local heating of a dense plasma by two crossing electron beams. Heating occurs as an instability of the electron beams drives Langmuir waves which couple nonlinearly into damped ion-acoustic waves. Simulations show a factor 2.8 increase in electron kinetic energy with a coupling efficiency of 18%. Our results support applications to the production of warm dense matter and as a driver for inertial fusion plasmas.

Prospects for Multi-kJ Plasma Amplifiers

Optica Publishing Group (2016) fw5e.5

Authors:

James Sadler, Raoul Trines, Luke Ceurvorst, Naren Ratan, Muhammad Kasim, Robert Bingham, Peter Norreys

The generation and amplification of intergalactic magnetic fields in analogue laboratory experiments with high power lasers

Physics Reports Elsevier 601 (2015) 1-34

Authors:

Gianluca Gregori, Brian Reville, Francesco Miniati

Abstract:

The advent of high-power laser facilities has, in the past two decades, opened a new field of research where astrophysical environments can be scaled down to laboratory dimensions, while preserving the essential physics. This is due to the invariance of the equations of magneto-hydrodynamics to a class of similarity transformations. Here we review the relevant scaling relations and their application in laboratory astrophysics experiments with a focus on the generation and amplification of magnetic fields at cosmological shock waves. These arise during the collapse of protogalactic structures, resulting in the formation of high Mach number shocks in the intergalactic medium, which act as sources of vorticity in protogalaxies. The standard model for the origin of magnetic fields is via baroclinic generation from the resulting misaligned pressure and temperature gradients (the so-called Biermann battery process). While both experiment and numerical simulation have confirmed the occurrence of this mechanism at shocks, reconciling the resulting weak fields with present day observations is an un-solved problem, although it is generally accepted that turbulent motions of the weakly magnetised plasma plays a key role. Bridging the vast scale differences is a challenge both numerically and experimentally. A summary of novel laboratory experiments aimed at investigating additional processes that may shed light on these and other processes, such us turbulent amplification, resistive and collision-less plasma instabilities will be discussed in this review, particularly in relation to experiments using high power laser systems. The connection between laboratory shock waves and additional mechanisms, such as diffusive shock acceleration will be discussed. Finally, we will summarize the impact of laboratory investigation in furthering our understanding of plasma physics on super-galactic scales.